DOCSLIB.ORG

Planck-Scale Corrections to Friedmann Equation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Planck-Scale Corrections to Friedmann Equation Cent. Eur. J. Phys. • 12(4) • 2014 • 245-255 DOI: 10.2478/s11534-014-0441-3 Central European Journal of Physics Planck-scale corrections to Friedmann equation Research Article Adel Awad∗1,2,3, Ahmed Farag Ali† 1,4 1 Centre for Fundamental Physics, Zewail City of Science and Technology Sheikh Zayed, 12588, Giza, Egypt 2 Department of Physics, Faculty of Science, Ain Shams University, Cairo, 11566, Egypt 3 Center for Theoretical Physics, British University of Egypt, Sherouk City 11837, P.O. Box 43, Egypt 4 Department of Physics, Faculty of Science, Benha University, Benha 13518, Egypt Received 16 November 2013; accepted 18 January 2014 Abstract: Recently, Verlinde proposed that gravity is an emergent phenomenon which originates from an entropic force. In this work, we extend Verlinde’s proposal to accommodate generalized uncertainty principles (GUP), which are suggested by some approaches to quantum gravity such as string theory, black hole physics and doubly special relativity (DSR). Using Verlinde’s proposal and two known models of GUPs, we obtain modifications to Newton’s law of gravitation as well as the Friedmann equation. Our modification to the Friedmann equation includes higher powers of the Hubble parameter which is used to obtain a cor- responding Raychaudhuri equation. Solving this equation, we obtain a leading Planck-scale correction to Friedmann-Robertson-Walker (FRW) solutions for the p = ωρ equation of state. PACS (2008): 04.60.Bc;04.60.Cf;04.70.Dy Keywords: quantum gravity • entropic force • thermodynamics • black holes © Versita sp. z o.o. 1. Introduction mutation relations between position coordinates and mo- menta [1–8]. This can be understood in the context of string theory since strings can not interact at distances smaller than their size. The GUP is represented by the following One of the intriguing predictions of various frame works form [9–11]: of quantum gravity, such as string theory and black ~ hole physics, is the existence of a minimum measurable ∆xi∆pi ≥ [1 + β (∆p)2+ < p >2 2 length. This has given rise to the so-called generalized un- 2 2 + 2β ∆pi + < pi > ] ; (1) certainty principle (GUP) or equivalently, modified com- `2 p2 P p p β β / M c 2 β p M where = j j , = 0 ( p ) = 0 2 , p = Planck ∗ j ~ E-mail: [email protected] † E-mail: [email protected] (Corresponding author) mass, and Mpc2 = Planck energy. The inequality (1) is 245 Brought to you by | CERN library Authenticated Download Date | 10/4/17 1:58 PM Planck-scale corrections to Friedmann equation equivalent to the following modified Heisenberg algebra scales are only a few orders of magnitude less than Planck [9]: scale. [xi; pj ] = i~(δij + βδij p2 + 2βpipj ) : (2) Let us review Verlinde’s proposal [38] on the origin of grav- ity, where he suggested that a gravitational force might This form ensures, via the Jacobi identity, that be of an entropic nature. This assumption is based on the x ; x p ; p [ i j ] = 0 = [ i j ] [10]. relation between gravity and thermodynamics [40–42]. Ac- cording to thermodynamics and the holographic principle, Recently, a new form of GUP was proposed in [12, Verlinde’s approach results in Newton’s law of gravitation, 13], which predicts maximum observable momenta as well the Einstein Equations [38] and the Friedmann Equations as the existence of minimal measurable length, and is con- [43]. The theory can be summarized as sistent with doubly special relativity theories (DSR) [14– at the temperature T , the entropic force F of a gravita- 19], string theory and black holes physics [1–7]. It ensures tional system is given as: [xi; xj ] = 0 = [pi; pj ], via the Jacobi identity. F∆x = T ∆S; (4) h p p x ; p i δ − α pδ i j [ i j ]= ~ ij ij + p where ∆S is the change in the entropy such that, at a i x + α2 p2δij + 3pipj ; (3) displacement ∆ , each particle carries its own portion of entropy change. From the correspondence between the entropy change ∆S and the information about the bound- α α /Mpc α `p/~;Mp `p where = 0 = 0 = Planck mass, = ary of the system and using Bekenstein’s argument [40– Mpc2 Planck length, and = Planck energy. In a series 42], it is assumed that ∆S = 2πkB, where ∆x = ~/m and of papers, various applications of the new model of GUP kB is the Boltzmann constant. have been investigated [20–33]. mc The upper bounds on the GUP parameter α has been ∆S = 2πkB ∆x; (5) derived in [22]. It was suggested that these bounds can ~ be measured using quantum optics and gravitational wave where m is the mass of the elementary component, c is techniques in [34, 35]. Recently, Bekenstein [36, 37] pro- speed of light and ~ is the Planck constant. posed that quantum gravitational effects could be tested The holographic principle assumes that for a region en- experimentally, suggesting“a tabletop experiment which, closed by some surface gravity can be represented by the given state of the art ultrahigh vacuum and cryogenic degrees of freedom on the surface itself and independent technology, could already be sensitive enough to detect of the its bulk geometry. This implies that the quantum Planck scale signals” [36]. This would enable several gravity can be described by a topological quantum field quantum gravity predictions to be tested in the Laboratory theory, for which all physical degrees of freedom can be [34, 35]. This is considered as a milestone in the field of projected onto the boundary [44]. The information about quantum gravity phenomenology. the holographic system is given by N bits forming an ideal Motivated by the above arguments, we investigate pos- gas. It is conjectured that N is proportional to the entropy sible effects of GUP on the Friedmann equation. We use of the holographic screen, the entropic force approach suggested by Verlinde [38] to calculate corrections to Newton’s law of gravitation and the Friedmann equations for two models of GUP, which 4S N = ; (6) are mentioned above. We found that Planck-scale cor- kB rections to the Friedmann equation include higher pow- ers of the Hubble parameter which are suppressed by then according to Bekenstein’s entropy-area relation [40– Planck length. Using these corrections we construct the 42] corresponding Raychaudhuri equations, which we then kBc3 S = A: (7) solve to obtain a leading Planck-scale correction to the 4G~ Friedmann-Robertson-Walker (FRW) solutions with equa- Therefore, one gets tion of state p = ωρ. Deriving the effects of GUPs on Newton’s law of gravitation through the entropic force Ac3 4πr2c3 N = = ; (8) approach was initially reported in [39] where a modi- G~ G~ fied Newton’s law of gravitation was calculated. A possi- ble application of these Planck-scale corrections is early where r is the radius of the gravitational system and A = cosmology, in particular inflation models where physical 4πr2 is area of the holographic screen. It is assumed that 246 Brought to you by | CERN library Authenticated Download Date | 10/4/17 1:58 PM Adel Awad, Ahmed Farag Ali each bit emerges out of the holographic screen i.e. in one 2. GUP-quadratic in ∆p and BH dimension. Therefore each bit carries an energy equal thermodynamics to kBT/2. Using the equipartition rule to calculate the energy of the system, one gets In this section, we review the modified thermodynamics of the black hole which yields a modified entropy due to πc3r2 E 1 Nk T 2 k T Mc2: GUP [56–62]. Using the holographic principle, we get a = B = G B = (9) 2 ~ modified number of bits N which yields quantum gravity corrections to Newton’s law of gravitation and the Fried- By substituting Eq. (4) and Eq. (5) into Eq. (9), we get mann equations. Black holes are considered as a good laboratories for the Mm clear connection between thermodynamics and gravity, so F G ; = r2 (10) black hole thermodynamics will be analyzed in this sec- tion. We then make an analysis of BH thermodynamics p making it clear that Newton’s law of gravitation can be if the GUP-quadratic in ∆ that was proposed in [1–11] derived . is taken into consideration. With Hawking radiation, the emitted particles are mostly photons and standard model Recently, a modified Newton’s law of gravity due to (SM) particles. Using the Hawking-Uncertainty Relation, Planck-scale effects through the entropic force approach the characteristic energy of the emitted particle can be was derived by one of the authors [39]. Derivation of identified [56–60]. It has been found [25, 26], assuming Planck scale effects on the Newton’s law of gravity are some symmetry conditions from the propagation of Hawk- based on the following procedure: modified theory of grav- ing radiation, that the inequality that would correspond ity → modified black hole entropy→ modified holographic to Eq. (1) can be written as follows: surface entropy → Newton’s law corrections . This proce- ~ p2 x p ≥ 5 µ β `2 ∆ : dure has been followed with other approaches like non- ∆ ∆ 1 + (1 + ) 0 p (11) 2 3 ~2 commutative geometry in [45–48]. In this paper, we take 2:821 2 into account the quantum gravity corrections due to GUP where µ = π . in the entropic-force approach, following the same proce- By solving the inequality (11) as a quadratic equation in dure as [39], and extend our study to calculate the modified ∆p, we obtain Friedmann and Raychaudhuri equations. To calculate the quantum gravity corrections to the Friedmann equations, s we use the procedure that has been followed in [49, 50].
Load more

Recommended publications
  • Arxiv:1903.02940V2
    Proton decay and the quantum structure of spacetime 1, 1, 2,3, 4,5, Abeer Al-Modlej, ∗ Salwa Alsaleh, † Hassan Alshal, ‡ and Ahmed Farag Ali § 1 Department of Physics and Astronomy, King Saud University, Riyadh 11451, Saudi Arabia 2Department of Physics, University of Miami, Coral Gables, FL 33124, USA 3Department of Physics, Faculty of Science, Cairo University, Giza 12613, Egypt 4Department of Physics, Faculty of Science, Benha University, Benha, 13518, Egypt 5Quantum Gravity Research, Los Angeles, CA 90290, USA (Dated: October 29, 2019) Abstract Virtual black holes in noncommutative spacetime are investigated using coordinate coherent state formalism such that the event horizon of black hole is manipulated by smearing it with a Gaussian of width √θ, where θ is the noncommutativity parameter. Proton lifetime, the main associated phenomenology of the noncommutative virtual black holes, has been studied: first in 4 dimensional spacetime and then generalized to D dimensions. The lifetime depends on θ and the number of spacetime dimensions such that it emphasizes on the measurement of proton lifetime as a potential probe for the micro-structure of spacetime. Introduction promising to divulge many secrets about how nature works on quantum gravity level [22]. A black hole with 9 mass of Sun would have TBH 60 10− K at the event Since the introduction of Hawking radiation [1], horizon, while a black hole with∼ mass× of Earth’s moon geometrical many semiclassical, non-classical [2–9] and would have the surface temperature 2.7 K. So the ra- [10–12] endeavours—seeking “the” unified theory—have diation of astrophysical massive black∼ hole is too minute been striving to “shoehorn” general relativity into the to be detected in the Cosmic Microwave Background framework of quantum field theories (QFT).
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE Professor Abdel Nasser TAWFIK (Habilitation/Academician) Dr.Sc., Dr.rer.Nat (Ph.D.) Status: January 2015 Personal Information Name: Abdel Nasser TAWFIK Nationality: Egyptian/German Date of Birth: 22nd June 1967 Place of Birth: Sohag, Egypt Marital Status: Married Home Address (Egypt): El-Fardous City (6th-of-October City), Bld 42/112, Giza-Egypt Home Address (Germany): 13 Frohnauer Str., D-33619 Bielefeld-Germany Work Address: MTI University, Faculty of Engineering, Al-Hadaba Al- Wusta, Al-Mukattam, Cairo-Egypt Cell Phone: +201002390604 and +201120059074 E-Mail: [email protected], [email protected], and [email protected] URL: http://atawfik.net/ Wikipedia: http://en.wikipedia.org/wiki/Abdel_Nasser_Tawfik Academic Positions Current: 1. Founding Director of the World Laboratory for Cosmology and Particle Physics (WLCAPP) http://wlcapp.net/, http://www.worldlab.ch/ 2. Founding Director of the Egyptian Center for Theoretical Physics (ECTP) http://www.mti.edu.eg/mti/page.aspx?pageID=95 3. Professor at the Modern University for Technology and Information (MTI University), Faculty of Engineering, http://www.mti.edu.eg/ 4. Team Leader of the Egyptian Groups of Scientists engaged to the ALICE Experiment at the Large Hadron Collider (LHC) at CERN, Geneva, Switzerland 5. Team Leader of the Egyptian Groups of Scientists engaged to the STAR Experiment at the Relativistic Heavy-Ion Collider (RHIC) BNL, USA 6. Team Leader of the Egyptian Groups of Scientists engaged to MPD Experiment at the NICA Facility at the Joint-Institute for Nuclear Research (JINR) Dubna, Russia 7. Team Leader of the Egyptian Groups of Scientists engaged to CBM Experiment at the FAIR Facility of Helmhortz Association (GSI) Darmstadt, Germany 8.
    [Show full text]
  • Curriculum Vitae SAURYA DAS
    Curriculum Vitae SAURYA DAS Personal details Date of birth: 30 June 1970 Nationalites: Canadian, Indian Languages: English, Bengali, Hindi (fluent), French (fair) Current position Professor of Physics, Department of Physics and Astronomy University of Lethbridge, Alberta, Canada Contact information Department of Physics and Astronomy, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada E-mail: [email protected] Telephone: +1-403-329-2689 http://directory.uleth.ca/users/saurya.das http://scholar.ulethbridge.ca/sauryadas http://www.researchgate.net/profile/Saurya Das Other/previous positions • Affiliate Member, Perimeter Institute of Theoretical Physics, Waterloo, Canada. • Theme Leader, Quantum Foundations and Quantum Gravity, Quantum Alberta (Universities of Alberta, Calgary and Lethbridge). • 2008 - 2013: Associate Professor of Physics (tenured), University of Lethbridge, Alberta, Canada. Became a Full Professor in 2013. • 2003 - 2008: Assistant Professor of Physics, University of Lethbridge, Alberta, CANADA. • 2002 - 2003: Postdoctoral Fellow at University of New Brunswick, Fredericton, Canada. • 2000 - 2002: Postdoctoral Fellow at The University of Winnipeg & Winnipeg Institute for Theoretical Physics, Winnipeg, CANADA. • 1998 - 2000: Postdoctoral Fellow at The Center for Gravitational Physics and Geometry, The Pennsylvania State University, U.S.A. • 1994 - 1998: Research Fellow at The Institute of Mathematical Sciences, Chennai, India. Education and awards • Ph.D. in Theoretical Physics from The Institute of Mathematical Sciences, Chennai, India (1999). • First class in M.Sc. (by research) in Theoretical Physics from Anna University, Chennai, India (1994). • First class in B.Sc. (Physics Honours) from Presidency College, University of Calcutta, Kolkata, India (1992) - ranked second in the University. • Awards: Best Ph.D Thesis Award. Honorable Mention in the Gravity Research Foundation Essay Competitions - 2001, 2007, 2014, 2015, 2016.
    [Show full text]
  • Curriculum Vitae SAURYA DAS
    Curriculum Vitae SAURYA DAS Personal details Date of birth: 30 June 1970 Citizenship: Canadian Languages: English, Bengali, Hindi (fluent), French (functional) Current position Professor of Physics, Department of Physics and Astronomy University of Lethbridge, Alberta, Canada Contact information Department of Physics and Astronomy, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada E-mail: [email protected] Telephone: +1-403-329-2689 http://directory.uleth.ca/users/saurya.das http://scholar.ulethbridge.ca/sauryadas http://www.researchgate.net/profile/Saurya Das Other/previous positions • Affiliate Member, Perimeter Institute of Theoretical Physics, Waterloo, Canada. • Theme Leader, Quantum Foundations and Quantum Gravity, Quantum Alberta (Universities of Alberta, Calgary and Lethbridge). • Full Professor of Physics University of Lethbridge, Alberta, Canada. • 2008 - 2013: Associate Professor of Physics (tenured), University of Lethbridge, Alberta, Canada. • 2003 - 2008: Assistant Professor of Physics, University of Lethbridge, Alberta, CANADA. • 2002 - 2003: Postdoctoral Fellow at University of New Brunswick, Fredericton, Canada. • 2000 - 2002: Postdoctoral Fellow at The University of Winnipeg & Winnipeg Institute for Theoretical Physics, Winnipeg, CANADA. • 1998 - 2000: Postdoctoral Fellow at The Center for Gravitational Physics and Geometry, The Pennsylvania State University, U.S.A. • 1994 - 1998: Research Fellow at The Institute of Mathematical Sciences, Chennai, India. Education and awards • Ph.D. in Theoretical Physics from The Institute of Mathematical Sciences, Chennai, India (1999). • First class in M.Sc. (by research) in Theoretical Physics from Anna University, Chennai, India (1994). • First class in B.Sc. (Physics Honours) from Presidency College, University of Calcutta, Kolkata, India (1992) - ranked second in the University. 1 • Awards: Best Ph.D Thesis Award.
    [Show full text]
  • Aspects of Quantum Gravity
    ASPECTS OF QUANTUM GRAVITY AHMED FARAG ALI Master of Science, Benha University, 2008 A Thesis Submitted to the School of Graduate Studies of the University of Lethbridge in Partial Fulfilment of the Requirements for the Degree DOCTOR OF PHILOSOPHY Department of Physics and Astronomy University of Lethbridge LETHBRIDGE, ALBERTA, CANADA c Ahmed Farag Ali, 2012 Dedication To Ebtesam, Ibrahim, and my parents. iii Abstract We propose a Generalized Uncertainty Principle(GUP) consistent with String Theory, Black Hole Physics and Doubly Special Relativity. This modifies all quantum mechan- ical Hamiltonians and predicts quantum gravity corrections. We compute corrections to the Lamb shift, simple harmonic oscillator, Landau levels, and the tunneling cur- rent. When applied to an elementary particle, it suggests that the space must be quantized, and that all measurable lengths are quantized in units of a fundamental length. We investigated whether GUP can explain the violation of the equivalence principle at small length scales that was observed experimentally. We investigated the consequences of GUP on Liouville theorem. We examined GUP effect on post inflation preheating, and show that it predicts an increase or a decrease in parametric resonance and a change in particle production. The effect of GUP on the creation of black holes is investigated to justify the experimental results from the Large Hadron Collider. iv Acknowledgements First and foremost, I would like to express about my deep gratitude for my supervisor Dr. Saurya Das whose expertise and attention to both detail and the big picture, provided invaluable guidance for my research, all the while being so friendly and straightforward during our discussions.
    [Show full text]
  • Table of Contents (Print)
    PHYSICAL REVIEW D PERIODICALS For editorial and subscription correspondence, Postmaster send address changes to: please see inside front cover (ISSN: 1550-7998) APS Subscription Services P.O. Box 41 Annapolis Junction, MD 20701 THIRD SERIES, VOLUME 99, NUMBER 8 CONTENTS D15 APRIL 2019 The Table of Contents is a total listing of Parts A and B. Part A consists of articles 081501–084027, and Part B articles 084028–089901(E) PART A RAPID COMMUNICATIONS Marolf-Ori singularity inside fast spinning black holes (5 pages) ................................................................. 081501(R) Lior M. Burko and Gaurav Khanna ARTICLES LISA Pathfinder platform stability and drag-free performance (14 pages) ....................................................... 082001 M. Armano et al. (LISA Pathfinder Collaboration) Classifying the unknown: Discovering novel gravitational-wave detector glitches using similarity learning (8 pages) ..... 082002 S. Coughlin, S. Bahaadini, N. Rohani, M. Zevin, O. Patane, M. Harandi, C. Jackson, V. Noroozi, S. Allen, J. Areeda, M. Coughlin, P. Ruiz, C. P. L. Berry, K. Crowston, A. K. Katsaggelos, A. Lundgren, C. Østerlund, J. R. Smith, L. Trouille, and V. Kalogera Searching for low-mass dark matter particles with a massive Ge bolometer operated above ground (15 pages) .......... 082003 E. Armengaud et al. (EDELWEISS Collaboration) Optimizing the choice of analysis method for all-sky searches for continuous gravitational waves with Einstein@Home (12 pages) ............................................................................................................................... 082004 Sin´ead Walsh, Karl Wette, Maria Alessandra Papa, and Reinhard Prix Constraining the Johannsen deformation parameter ϵ3 with black hole x-ray data (10 pages) ............................... 083001 Ashutosh Tripathi, Askar B. Abdikamalov, Dimitry Ayzenberg, Cosimo Bambi, and Sourabh Nampalliwar Axionlike dark matter search using the storage ring EDM method (12 pages) ................................................
    [Show full text]
  • Albert Einstein
    Ahmed Farag Ali Department of Physics, Faculty of Science, Benha University Benha, Qaliubiya, 13518, Egypt Cell Phone: +20 112-668-1977 Fax: +20 133-213-511 E-mail: [email protected] ; [email protected]; [email protected] My page at INSPIREHEP: http://inspirehep.net/author/profile/Ahmed.Farag.Ali.1 My page at Google Scholar: http://scholar.google.com.eg/citations?user=fVCubX8AAAAJ Born: August 1, 1982. Current positions Assistant Professor, Department of Physics, Faculty of Science, Benha University, Egypt. Areas of specialization High Energy Physics; Astrophysics; Quantum Gravity Phenomenology; Cosmology and Black hole Physics. Appointments held 2012-currently • Assistant Professor, Physics Department, Faculty of Science, Benha University, Egypt. Feb - August 2015 • Visiting scientist , Department of Physics, Florida State University, USA. Jan 2013-2015 • Research Associate, Center for Fundamental Physics, Zewail City of Science and Technology, Egypt. 2008-2012 • Doctoral student and Teaching assistant at University of Lethbridge, Alberta, CANADA May-July 2008 • Visiting scientist at International Center for Theoretical Physics (ICTP), Trieste, Italy 2005-2008 • M. Sc. student and Demonstrator at Benha University, Benha, EGYPT. 2006-2007 • Diploma student at High Energy Physics Dept at ICTP, Trieste, ITALY. Jan-June 2006 • Visiting student at High Energy Department, Institute of Mathematical Sciences, Chennai, INDIA. 2003-2005 • Demonstrator at Physics Department, Faculty of Sciences, Benha University. 1 Education 2012 • PhD in Theoretical and Computational Physics, University of Lethbridge, Alberta, CANADA. 2008 • MSc in Theoretical Physics, Benha University. 2007 • Diploma in High Energy Physics, International Center for Theoretical Physics, Trieste, Italy. 2004 • Post-Graduate in theoretical Physics, Ain Shams University, Egypt.
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE :: PERSONAL DETAILS :: Name : Ahmed Farag Ali Date of birth : August 1st, 1982 Marital Status : Married Present Address: Department of Physics, Faculty of Science, Benha Center for Fundamental Physics, University, Zewail City of Science and Technology, Benha 13518, Qaliubiya, Egypt. Sheikh Zayed, 12588 Giza, Egypt. Official Email: [email protected] Official Email: [email protected] or My page @ Benha University Web. My page @Zewail City Web. Telephone : (+20) 127-964-8363 & (+20) 111-099-0926 Fax : (+20) 133-225-494 :: ACADEMIC EDUCATION :: 1. Ph.D. (2012) Major: Theoretical and Computational Physics, Thesis Title: Aspects of Quantum Gravity. University of Lethbridge, CANADA. 2. M. Sc. (2008) Major: Theoretical Physics Thesis Title: Phenomenological Aspects beyond the Standard Model Benha University, EGYPT. 3. ICTP Diploma (2007) Major: High energy Physics. Thesis titled: Fermions mixing and discrete symmetries. Abdus Salam International centre for theoretical physics (ICTP) Trieste, ITALY. 4. Postgraduate studies (2004) Major: Theoretical Physics Grade: 89% Ain Shams University, Cairo, EGYPT. 5. B.Sc.(2003) Major: Physics Grade: B.Sc., Excellent with First Class Honor. Benha University, EGYPT :: ACADEMIC POSITIONS :: Jan 2013- : Assistant Professor at Center for Fundamental Physics, Zewail City of Science and Technology. June 2012- : Assistant Professor at Physics Department, Faculty of Sciences, Benha University. 2008 – 2012 : Doctoral student and Teaching assistant at University of Lethbridge, Alberta, CANADA. 1 May-July 2008 : Visiting scientist at International Center for Theoretical Physics, Trieste, Italy. 2005-2008 : M. Sc. student and Demonstrator at Benha University, Benha, EGYPT. 2006-2007 : Diploma student at High Energy Physics Dept at ICTP, Trieste, ITALY.
    [Show full text]
  • Ahmed Farag Mohamed Ali CV Faragali11.Pdf
    CURRICULUM VITAE :: DR . AHMED FARAG ALI :: Personal Details Name : Ahmed Farag Ali Date of birth : August 1st , 1982 Marital Status : Married Nationality : Egyptian Present Address: Dr. Ahmed Farag Ali, Assistant Professor, Department of Physics, Center for Theoretical Physics Faculty of Sciences, Benha University, and Zewail City of Science and Technology Benha 13518, Qaliubiya, EGYPT. Sheikh Zayed District, 12588, 6th of October City, Giza, Egypt Official E-mails: [email protected] ; [email protected] ; [email protected] [email protected] (Alternate: [email protected] ) Tel: +(20)-12279648363. Fax: +(20)-133225494 Webpage @Benha U Web: http://www.bu.edu.eg/staff/ahmedali7 Webpage @Zewail City Web: http://www.zewailcity.edu.eg/research-institutes/ibs/ctp/staff/ahmed-farag/ :: ACADEMIC EDUCATION :: 1. Ph.D. (2012) Major: Theoretical High Energy Physics Thesis Title: Aspects of Quantum Gravity. University of Lethbridge, CANADA. 1 2. M. Sc. (2008) Major: Theoretical High Energy Physics Thesis Title: Phenomenological Aspects beyond the Standard Model Benha University, EGYPT. 3. ICTP Diploma (2007) Major: High energy Physics. Thesis titled: Fermions mixing and discrete symmetries. Abdus Salam International centre for theoretical physics (ICTP) Trieste, ITALY. 4. Postgraduate studies (2004) Major: Theoretical Physics Grade: 89% Ain Shams University, Cairo, EGYPT. 5. B.Sc. (2003) Major: Physics Grade: B.Sc., Excellent with First Class Honor Benha University, EGYPT :: ACADEMIC POSITIONS :: Jan 2013- : Assistant Professor at Center for Theoretical Physics, Zewail City of Science and Technology, EGYPT. June 2012- : Lecturer (Assistant Professor) at Physics Department, Faculty of Sciences, Benha University, Benha, EGYPT. Sept 2008 – Jan 2012 : Doctoral student and Teaching assistant at University of Lethbridge, Alberta, CANADA.
    [Show full text]
  • Aspects of Quantum Gravity
    ASPECTS OF QUANTUM GRAVITY AHMED FARAG ALI Master of Science, Benha University, 2008 A Thesis Submitted to the School of Graduate Studies of the University of Lethbridge in Partial Fulfilment of the Requirements for the Degree DOCTOR OF PHILOSOPHY Department of Physics and Astronomy University of Lethbridge LETHBRIDGE, ALBERTA, CANADA © Ahmed Farag Ali, 2012 Library and Archives Bibliotheque et Canada Archives Canada Published Heritage Direction du Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-88392-1 Our file Notre reference ISBN: 978-0-494-88392-1 NOTICE: AVIS: The author has granted a non­ L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distrbute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non­ support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation.
    [Show full text]
  • Download Special Issue
    Advances in High Energy Physics Phenomenological Aspects of Quantum Gravity and Modified Theories of Gravity Guest Editors: Ahmed Farag Ali, Giulia Gubitosi, Mir Faizal, and Barun Majumder Phenomenological Aspects of Quantum Gravity and Modified Theories of Gravity Advances in High Energy Physics Phenomenological Aspects of Quantum Gravity and Modified Theories of Gravity Guest Editors: Ahmed Farag Ali, Giulia Gubitosi, Mir Faizal, and Barun Majumder Copyright © 2017 Hindawi Publishing Corporation. All rights reserved. This is a special issue published in “Advances in High Energy Physics.” All articles are open access articles distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Editorial Board Luis A. Anchordoqui, USA Frank Filthaut, Netherlands Anastasios Petkou, Greece T. Asselmeyer-Maluga, Germany Chao-Qiang Geng, Taiwan Alexey A. Petrov, USA M. Battaglia, Switzerland Philippe Gras, France Thomas Rössler, Sweden Botio Betev, Switzerland Xiaochun He, USA J. José Sanz-Cillero, Spain Lorenzo Bianchini, Switzerland Filipe R. Joaquim, Portugal Edward Sarkisyan-Grinbaum, USA Burak Bilki, USA KyungK.Joo,RepublicofKorea Sally Seidel, USA Adrian Buzatu, UK Aurelio Juste, Spain George Siopsis, USA Rong-Gen Cai, China Michal Kreps, UK Luca Stanco, Italy Duncan L. Carlsmith, USA Ming Liu, USA Satyendra Thoudam, Netherlands Ashot Chilingarian, Armenia Enrico Lunghi, USA Smarajit Triambak, South Africa Anna Cimmino,
    [Show full text]
  • Arxiv:2105.05208V2 [Astro-Ph.CO] 18 May 2021 II.2.3
    Challenges for ΛCDM : An update L. Perivolaropoulos1, ∗ and F. Skara1, y 1Department of Physics, University of Ioannina, 45110 Ioannina, Greece (Dated: May 20, 2021) A number of challenges of the standard ΛCDM model has been emerging during the past few years as the accuracy of cosmological observations improves. In this review we discuss in a unified manner many existing signals in cosmological and astrophysical data that appear to be in some tension (2σ or larger) with the standard ΛCDM model as defined by the Planck18 parameter values. In addition to the major well studied 5σ challenge of ΛCDM (the Hubble H0 crisis) and other well known tensions (the growth tension and the lensing amplitude AL anomaly), we discuss a wide range of other less discussed less-standard signals which appear at a lower statistical significance level than the H0 tension (also known as 'curiosities' in the data) which may also constitute hints towards new physics. For example such signals include cosmic dipoles (the fine structure constant α, velocity and quasar dipoles), CMB asymmetries, BAO Lyα tension, age of the Universe issues, the Lithium problem, small scale curiosities like the core-cusp and missing satellite problems, quasars Hubble diagram, oscillating short range gravity signals etc. The goal of this pedagogical review is to collectively present the current status of these signals and their level of significance, with emphasis to the Hubble crisis and refer to recent resources where more details can be found for each signal. We also briefly discuss possible theoretical approaches that can potentially explain the non-standard nature of some of these signals.
    [Show full text]